Numerous postal systems have been developed around the world for the delivery of mail pieces, e.g., letters, flats, packages, and the like. In many situations, when a mail piece is received by a recipient entity, there is the need to authenticate the mailer (sender) of a given mail piece before opening it or taking some other action. This is especially true when the recipient entity is a business or other large entity where all incoming mail is processed in a central mail room for internal delivery throughout the entity. The authentication of the mailer is usually accomplished by examining the return address on the mail piece. This form of authentication, however, is not completely trustworthy as the return address on a mail piece can easily be manipulated or forged in order to deceive the recipient.
It would be desirable, therefore, to be able to positively authenticate the mailer of a mail piece in a manner that is trustworthy and not easily susceptible to fraudulent manipulation.